Method of felting keratinous articles



Allg- 1, 1967 J. c. azosmmnv METHOD OF FELTING KERATINOUS ARTICLES Filed March l5, 1965 m ww mu M C N vw V n a $222.@ A; a 52325; n om l! ATTOR IYS United States Patent O 9 claims. (l. as me) This invention relates to the felting of cloth articles. Felting is an industrial operation which is customarily used in the manufacture of different keratin-ous articles such as blankets, hats, industrial felts and some articles of clothing. Felting is characterized by substantial shrinking of the articles and by an increase in the weight per unit of the surface of the material treated. In the case of woven or knitted articles the operation is characterized to some extent by the disappearance of the pattern of the cloth.

Felting is generally carried out by submitting the material to intense mechanical working in an acid or alkaline aqueous solution, usually in a felting machine, for instace a mallet machine, the treatment frequently requiring 14 to 16 hours. Beyond the time consumed there are other inconveniences, including a substantial loss of weight, and the degradation of the textile fibers. This degradation involves the reduction of the mechanical qualities of the textile fibers, a loss of life, and poor iiexibility and hand.

It is an object of this invention to Isubject keratinous articles to an improved felting operation which reduces these objections to an inconsiderable level. Another object is to produce felted articles of higher quality than those produced by the prior art. Other objects are to improve the hand, the life, the appearance and the durability -of felted articles;

The objects of the invention are accomplished, generally speaking, by felting keratinous articles by agitation in a bath having as its essential felting ingredients a major proportion of a liquid hydrocarbon, which may be halogenated, and a `substantial proportion of water. In accomplishing this, apparatus has been sought which includes a chamber, a rotary drum therein, means to `supply the chamber with a bath comprising water and an inert hydrocarbon, a reservoir for such bath connected to the tank by a iilter and by a return line, means to control the temperature of the bath, means t-o empty the tank of fluid, means to drive the drum at treating and at centrifuging speeds, means to recover bath vapor from the gases in the chamber, and temperature control means for the chamber.

According to the present invention keratin-ous materials, for instancewool, are felted by a controlled mechanical treatment in a bath, the essential element of which is a hydrocarbon which may be halogenated or not and which may include the alkyl and alkylene, that is to say the saturated and the unsaturated, types. i

In the preferred method the material to be treated is subjected to repeated immersions in the treating bath. It is generally advantageous to vary the intensity of the mechanical action on the treated articles during the course of the treatment by reducing the volume of the bath, which changes the effect -of plunging the articles into the bath, and reduces the time of immersion. According to another method of the process the material is agitated in ice the bath without being removed, preferably with frequent and vigorous reversal of direction.

Among the hydrocarbons which are useful in this felting operation is a heavy petroleum fraction, having a boiling point between 1GO-300 C. and preferably between 15G-210 C. The hydrocarbons may be saturated or unsaturated, halogenated or not. The halogens most employed as substituents on the hydrocarbons are chlorine or fluorine. Among such hydrocarbons are triiiuorotrichlorethane, trichlorethane, dichloropropane, dichlorodiuoroethane, trichlorethylene, tetrachlorethylene and dichlorethylene.

In carrying out the process it is preferred to introduce into the felting bath a quantity of water which is between 20-60% of the weight of the dry articles undergoing treatment. This water may be included in the bath ori ginally or added as the treatment proceeds either all at once or in steps. It is advantageous to include dispersing agents in the bath so as to facilitate the dispersi-on of the aqueous phase in the organic phase. These dispersing agents may be ,surface active agents of anionic type, such as the sulfates of fatty alcohols, or cationic type, such as the derivatives of quaternary ammonium compounds, or nonionic such as the derivatives of ethylene oxide. The quantity of dispersing agent introduced depends upon the nature of the organic phase chosen and on the quantity of water included. The water is generally in minor percent and the organic phase in major percent, but they may be present in a proportion up to about 1:1 by weight.

i According to another characteristic, the invention is employed at temperatures below the boiling point of the constituents of the bath, the temperature generally being between 30 and 70 C. and preferably around 50 C.

The process is readily accomplished in an apparatus which contains as its essential element a chamber including a rotary drum which is partially submerged in the bath. The drum is preferably a forarninous cylinder mounted revolvably on a horizontal axis and capable of being driven at different speeds, of which lower speeds are used to treat the goods and higher speeds are used to spin the goods dry. The satisfactory proportion of diameter to depth is 1:5. This drum can be rotated in one direction or it can be alternated in direction. The interior of the `drum can be equipped with prongs or pins or other structures designed to catch and lift the articles.

During the operation of felting, properly so called, the drum is rotated so as to carry the articles to the upper part from which they are released and fall by gravity into the bath. For example, for a drum of about cm. in diameter and 35 cm. in depth, the speed of rotation may be on the Iorder of 35 rpm., this being a satisfactory speed of rotation in most cases. The maintenance of the temperature of the treating bath is of some importance and it is advisable to incorporate an electrical or steam heating coil to maintain a proper, selected` temperature.

It is favorable to supply the apparatus with a circulatory system for the treating bath so that the bath can be continuously filtered and heated outside the chamber. For this purpose one can incorporate a pump and a reservoir which not only permit the recycling of the liquid at proper temperature, but provide for the treating of the chamber during the spin drying or centrifuging.

It is advantageous to associate with this apparatus a dryer, for example a hot air dryer, so that the treated article can be freed of residual treating bath, and with means for recovering any hydrocarbon which escapes from the bath as a gas.

The above and further object and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing is for the purpose of illustral tion only and is not intended as a definition of the limits of the invention.

In the drawing, wherein like reference characters refer to like parts throughout the several views,

The ligure is a diagrammatic view of apparatus accord ing to the invention, in which 10 indicates a treating chamber which is enclosed and which is supplied with water and a hydrocarbon from a storage tank 11 by means of a cond-uit 12. Within the chamber 10 is a drum 13 which has a foraminous rim and is mounted on bearings not shown. To one of the axles is attached the shaft of a motor 14 of variable speed, the speeds of which may be changed from those which are satisfactory for felting to those which are satisfactory for the centrifugal drying of the goods. The perforation in the walls of the drum are indicated at 15. They admit some of the bath during felting and they permit its escape from the goods during drying. The interior'wall of the drum is also provided with steps or paddles 16 which serve to carry the goods and lift them up to the top, from whence they fall down into the treating bath once more. A door 17 in the wall of the chamber gives access to the interior of the chamber and the drum. A conduit 18 connects the chamber with the filter 19' and pump 20 serves to drive the fluid in the conduit into the upper part of the reservoir 11. This reservoir may be supplied with water through line 21 and with hydrocarbon through a line 22. The heating coil 23 is supplied with hot water, steam or electricity depending upon the nature of the coil. The apparatus does not require automatic temperature control because this can usually be controlled manually7 but the chamber 10l may be provided with a thermostat 24 which is connected electrically to a pump 25 in the heating coil line 23. This assumes that the heating coil is supplied with a hot fluid. The construction of such automatic heat control is well known and is not novel in itself.

The upper portion Iof the chamber 10 is connected by a line 26 to a solvent trap 27. The air line 28 is connected to a ventilator 29 which is, in turn, connected to the upper portion of the chamber. The material in the drum, after the felting bath has been drained off, can be dried by admitting air from line 28 through valve 30 and ventilator 29 to the interior of the chamber where it dries the felted material and is discharged to the solvent trap 27. The air from line 28 will normally be used at elevated temperature so as to evaporate the hydrocarbons retained in the felted material. It is preferably assisted by rotating the drum at a speed which spins residual liquid out of the material. The speeds employed in household and commercial washing machines and spin dryers, and the chambers employed in such apparatus are suitable in the present use. The solvent trap 27 receives the vapors through line 26 and extracts the hydrocarbons therefrom. The escape of gasses stripped of their hydrocarbons can be assisted by flowing air through the line 31, which acts as an aspirator to draw the fumes through the trap. A valve 32 enables one to control the degree of vacuum exerted by the aspirator.

It is advantageous to supply the apparatus with circulating means for the treating bath, including a pump, a filter and a reservoir so that the liquid can be cleaned and recycled either continuously or intermittently.

Instead of heating the liquid in the storage tank the heater can be applied in the felting bath containing the goods beneath the liquid level.

It is also convenient to associate means for drying the treated merchandise with the apparatus, for example a hot air dryer, as well as means for recovering the hydrocarbons. This may involve, for example, a still and condenser which will separate hydrocarbons from associated liquids. Decantation apparatus can also be employed, particularly in large installations which employ hydrocarbons which readily isolate themselves from the accompanying water.

In the apparatus illustrated and described the process is carried out by putting the articles to be treated, a number of berets, into the drum of the machine. The apparent volume of the articles may conveniently represent up to 50% of the volume of the drum and it is advantageous to choose the weight of dry materials introduced with respect to the volume of the bath between l/ZS and l/ 1, a preferred ratio lying between l/ 15 and 1/ 3, the weight being measured in kilograms and the volume in liters. The drum is rotated so as to submit the articles to be repeated immersions in the bath, the temperature being maintained upward of about 50 C. but below the point of active vaporization of the particular liquid employed. This treatment is continued until the chosen degree of felting has been reached. This will be a function of the nature of the articles treated and of the conditions employed. It may run anywhere from 30 lminutes to 3 hours.

After the treatment is completed the articles are dried, preferably by draining the tank of liquid and filling it with hot air. The drum may be rotated or not during the drying, as desired.

It is also within the scope of the invention to introduce variance into the method of operation described. It is possible, for example, to change the temperature during operation. It is equally possible to begin the felting treatment for a short time, for example 10-30 minutes, with a ratio of about 1/ 25 and with a quantity of water about 20% of the weight of the dried articles, thereafter changing to the preferred constitution and conditions.

It is also satisfactory under some conditions to reduce the quantity of the bath present in the drum, that is to say to lower the level 'of the liquid in the chamber or tank so that it covers less of the lower part of the drum, and it is also helpful at times to introduce more water into the bath, so as to produce a ratio of about 1:5 and a total quantity of Water up to about 50% of the weight of the articles treated.

It is equally within the scope of the invention to employ preliminary 'or after treatments, for example im permeabilization, bleaching, softening, for instance by a means of a standard fabric softener, or to employ antistatic or bacteriacide treatments.

The folllowing examples are illustrative of the invention and do not limit the scope of what is elsewhere hercin stated and claimed:

Example I A closed chamber containing a perforated, stainless steel drum 815 mm. in diameter and 335 mm. wide capable of being driven at 35 r.p.m., is connected to a reservoir so located as to supply the chamber by gravity. A circulating pump is located in the pipeline which extends from the bottom of the chamber to the top of the reservoir. The pipeline also contains a filter and an electric heater. The heater may be in the chamber, in the line, or in the reservoir. The articles submitted to felting are knitted wool berets 44 cm. in diameter weighing about 75 g. apiece. These berets contain about 6% by weight of oiling and greasing compound (lubricants) of standard types. About 3 kg. of these berets are put into the drum and the chamber receives about 70 liters of tetrachloroethylene at 64 C., 600 g. of water, and 600 g. of a commercial emulsiiier of any surface active, anionic or nonionic type. The drum is rotated for 10 minutes and then an additional 900 g. of water and 900 g. of emulsier are added. The treatment is continued for 30 minutes then the Volume of the bath is reduced to about 35 liters, the treatment being continued for 90 minutes under these conditions. The bath is continuously circulated and filtered during this treatment while maintaining a temperature of about 64 C.

After treatingthe chamber the berets are centrifuged in the drum at high speeds and dried by air at 70 C. The berets, as withdrawn from the chamber, have a diameter of 23 cm. which indicates a dimensional reduction in size of 48%. They weigh 70 g. each which, considering the removal of 6% oils and grease, corresponds to a lossof wool of only .7%.

The berets obtained have a hand and life which is substantially superior to that of the same berets when treated by known techniques in aqueous alkaline or acid medium. In order to obtain a dimensional reduction of 50%, the prior art technique required about 6 to 8 hours and resulted in a loss of about of the wool.

The berets produced by this invention have a resistance to distortion of 7.08 kg./cm.2, whereas like materials when treated by the process of the prior art have a resistance of only 6.02 kg./cm.2, both measurements being by the system AFNOR NF .G00.002.

Example 2 Operating as in Example l with this difference, that one simply treats the berets with 70 liters of tetrachlorethylene, 1500 g. of water and 1500 g. of emulsifier for 2 hours at 50 C. This produces berets 30 cm. in diameter, a dimensional reduction of 32%, and a hand and life comparable to the berets of Example 1.

Example 3 One operates in the same apparatus as Example 1 with 3 kg, of woven woolen blankets containing 10% polyamide fibers and 4% of wool grease. The treatment is started with a mixture of 70 liters of tetrachlorethylene 600 g. of water and 600 g. of emulsifier, the preliminary heating being for 10 minutes at 42 C. Thereafter there is added 450 g. of water and 450 g. of emulsier, and the treatment is continued at 42 C. for 15 minutes. After spinning and drying, the blankets have a dimensional reduction of 27.4% in length and 4.8% in width. The loss of textile materials is 4.1%. The blankets thus treated have a woolly, soft appearance which approximates those of finished articles. This has the advantage that it makes it possible to materially reduce the surface working which has previously been employed to raise the nap.

Example 4 Using the apparatus of Example 1 with 3 kg. of Wool down, containing 4% of wool lubricant, the treatment is begun with a mixture of 70 liters of tetrachlorethylene, 600 g. of water and 600 g. of emuisifier. This treatment continues for 10 minutes at 62 C., there is added to the bath 900 g. of water and 900 g. of emulsilier, and the treatment is continued for minutes. The volume of the bath is reduced to liters without modifying its composition, and the operation is continued while circulating the bath through a filter for 1 hour and 30 minutes. After wringing and drying there is obtained a wool down having a hand and life substantially superior to those of wool down felted in the aqueous acid or alkaline media of the prior art. The dimensional reduction is 35.5% in length and 13.6% in width.

Example 5 article has an aspect which is particularly lively and woolly. The shrinkage is in length and 34% in width. The loss of Wool is about 3.7%.

With respect to the prior art, the process of this invention has several important advantages. The duration of treatment is considerably reduced when it is desired to attain degrees of felting which were previously either unobtainable or very difficult to obtain. The fibers are not degraded during treatment, a very substantial advantage, and the loss of weight of the keratinous materials is materially reduced. There is an improvement in the physical qualities of the felted articles, such as their mechanical resistance; the life, the feel and the appearance of the articles are substantially improved compared to prior art articles produced by the best known prior art methods. The lubricated articles submitted to felting are degreased by the organic contents of the felting bath, and this is particularly advantageous with respect to known proc` esses, which require a separate degreasing operation.

It is particularly important that the articles may be dried in the very apparatus in which the felting takes place. Another advantage resides in the excellent uniformity of result, that is to say in reproduceability of the process. Known felting processes do not permit the production of such uniform products either in one operation or in a series of operation.

Other advantages of the invention are in the accomplishment of the objects of the invention as stated hereinabove.

As many apparently widely different embodiments of the present invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments.

What is claimed is:

1. A method of felting keratinous articles which comprises repeatedly and sequentially immersing the articles in, and withdrawing them from a bath having as its essential felting ingredients a substantial proportion of a liquid hydrocarbon, which may be halogenated, and a substantial proportion of water, while maintaining the bath at substantially constant temperature with a range of about 30 to 70 C., and preferably above 50 C.

2. A method according to claim 1 in which the hydrocarbon is a heavy petroleum fraction boiling between about and about 210 C.

3. A method according to claim 1 in which the hydrocarbon is of a type represented by triuorotrichloroethane, trichloroethane, dichloropropane, dichlorodiiluoroethane, trichlorethylene, tetrachlorethylene, and dichlorethylene.

4. A method according to claim 1 in which the ratio of the weight `of the dry articles in kg. to the volume of the bath in liters is between about 1/1 and -about 1/25, the water is present at about 20 to 60% of the weight of the dry articles.

S. A method according to claim 4 and adding a surface active agent as an ingredient of the bath.

6. A method according to claim 4 which includes the step of reducing the quantity of the felting bath during the felting treatment.

7. A method according to claim 4 which includes the steps of draining the liquid from the felted articles, centrifuging the :articles to further reduce the content of liquid, drying the articles, and recovering the liquid from each such step.

8. A method according to claim 4 in which the water is added to the -felting bath in separate increments during the process of felting.

9. A method of felting keratinous articles which comprises repeatedly and sequentially immersing the articles in and withdrawing them from a felting bath containing as the felting ingredients a liquid hydrocarbon, which may be halogenated, and water, in a substantial proportion of each, maintaining the temperature of the bath within a range of about 30 to 70 C., Vand preferably above 50 C., adding more water and repeating the sequential inimersion and withdrawal of the articles, in and from the bath, for a total period of about 30 minutes to two hours, and drying the articles.

(References on following page) References Cited UNITED STATES PATENTS Coghlan 8-139.1 Chudoba 28-72.3 X Mattin 28-723 Olsen 8-142 Reddish 8-142 IFluss 8-139.1 Mercier 8-112 Reider 28-723 X Lee 28-72.3 X

8 Matton et a1 2872.3 X Hofman 28-72.2 Smith 28-5 Gobel 28--5 Harris et a1 28-72.3 Huchles 28--72.3

Assistant Examiners. 

1. A METHOD OF FELTING KERATINOUS ARTICLES WHICH COMPRISES REPEATEDLY AND DEQUENTIALLY IMMERSING THE ARTICLES IN, AND WITHDRAWING THEM FROM A BATH HAVING AS ITS ESSENTIAL FELTING INGREDIENTS A SUBSTANTIAL PROPORTION OF A LIQUID HYDROCARBON, WHICH MAY BE HALOGENATED, AND A SUBSTANTIAL PROPORTION OF WATER, WHILE MAINTAINING THE BATH AT SUBSTANTIALLY CONSTANT TEMPERATURE WITH A RANGE OF ABOUT 30* TO 73*C., AND PREFERABLY ABOVE 50*C. 